Martín Alonso Pinzón, (Palos de la Frontera, Huelva; c. 1441 – c. 1493) was a Spanish mariner, shipbuilder, navigator and explorer, oldest of the Pinzón brothers. He sailed with Christopher Columbus on his first voyage to the New World in 1492, as captain of the Pinta. His youngest brother Vicente Yáñez Pinzón was captain of the Niña, and the middle brother Francisco Martín Pinzón was maestre (first mate) of the Pinta.
The Pinzón family was among the leading families of Palos de la Frontera in the late 15th century. There are several conflicting theories about the origin of the family and of their name (see Pinzón brothers#The Pinzón family of Palos). His grandfather was as sailor and diver known as Martín; it is not clear whether that was a first or last name, and whether in his generation Pinzón was a surname or an epithet. His father was a sailor named Martín Pinzón; his mother was named Mayor Vicente.
Born in Palos around 1441, it appears that at quite a young age Pinzón shipped out on a locally based caravel as a grumete (cabin boy). His home, now the Casa Museo de Martín Alonso Pinzón, was on the old royal road to the Monastery of La Rábida.